DESCRIPTION Compounds having the ability to interfere with microtubule mediated functions in the cell have become of recent interest as therapeutic agents, tools to probe the machinery of the cell,, as synthetic targets. The successful use of compounds in chemotherapeutic regiments, like Taxol, illustrate the medical importance of cytotoxic agents capable of interrupting the cellular role of microtubules. Ustiloxin A is a new member of this class of compounds that presents some interesting synthetic challenges. It is the goal of the proposed research to complete the total synthesis of ustiloxin A. In doing so, the synthesis of this unique 13 membered cyclic peptide will address some interesting bond constructions. The first of which is the asymmetric synthesis of a tertiary beta-aryloxy-alpha-amino acid utilizing a sequential asymmetric alkylation and reduction sequence. The second challenge to be addressed is the construction of a beta-hydroxy-alpha-amino acid by the asymmetric glycinamide aldol condensation with the requisite aldehyde. The purpose of this proposal will be to outline a concise synthetic plan to oxygenated alpha-amino acids and apply those proposed methods to the synthesis of ustiloxin A.